In the world of PriPara, a popular virtual theme park, girls can become idols by participating in singing, dancing, and fashion competitions that are broadcast worldwide. For elementary school student Laala Manaka, attending PriPara is strictly forbidden by her school, Paprika Private Academy. However, after accidentally returning a lost PriTicket to a girl named Mirei Minami, Laala is pulled into the PriPara world and makes an impromptu, successful idol debut.

Laala discovers that Mirei is actually her school's strict disciplinary committee president. The two decide to form an idol team and are managed by Kuma, a plush bear. They aspire to recruit the cool and popular idol Sophy Hojo, who has a quirky secret: she relies on eating pickled plums, known as Red Flashes, to switch from a dreamy Fancy Mode to her powerful Cool Mode. After helping Sophy, the three officially form the unit SoLaMi Smile. Their main rivals are the group Dressing Pafé, managed by a rabbit named Usagi and consisting of the strategic Go champion Sion Todo and the Canadian-Japanese twin duo Dorothy and Reona West.

As the series progresses, SoLaMi Smile and Dressing Pafé put aside their rivalry to form a supergroup called SoLaMi Dressing. Together, they compete against Falulu, a mysterious robotic vocal doll created from the collective wishes of girls who wanted to enter PriPara. The competition is for the legendary Paradise Coord. After winning and exchanging Friend Tickets with Falulu, Laala inadvertently causes Falulu to fall into a coma. SoLaMi Dressing performs a concert in their Paradise Coords, successfully reviving Falulu and giving her a more human heart before she departs for PriPari in France.

In the second season, a new area called the Dream Theater opens, and the grand PriPara Dream Parade event begins. Idols compete in dream teams of five to win the seasonal Dream Idol Grands Prix. New idols arrive, including the angel-devil duo Aromageddon, the gentle Fuwari Midorikaze, and the art teacher Ajimi Kiki. They face the mysterious Masked Genius, who steals competition coords. The Genius is revealed to be Hibiki Shikyoin, a powerful idol who takes over the PriPara system and transforms it into CelePara, banning all but a select few from performing. The remaining idols create an underground PriPara to rebel. After several competitions, a team called FriendAll wins the Spring Grand Prix, restoring the original PriPara.

The third season introduces the Divine Idol Grand Prix to crown the next divine idol. The system is upgraded with jewels, and Laala finds a mysterious baby named Jewlulu who has fallen from the sky and calls her Mama. It is soon revealed that Jewlulu is actually Jewlie, the missing divine idol who has been reduced to an infant state. The idols are tasked with raising her to unlock her power and earn Super Cyalume Coords. Laala is shocked to learn that the new virtual idol unit Triangle is actually managed by her younger sister Non, who is secretly competing to surpass her. New rivals like the energetic Pepper Taiyou and the celebrity Chiri Tsukikawa also emerge. After several Grand Prix events, SoLaMi Smile ultimately wins and is crowned the new divine idol, while Jewlie is restored and reborn as a new goddess.